Method of and apparatus for making dentures



July 17, 1956 J. HlGHKlN 2,754,589

METHOD OF AND APPARATUS FOR MAKING DENTURES Filed Aug. 20, 1954 3Sheets-Sheet 1 g 59 59 990 wa 9 F I G .6

6m FIG .7

INVEN TOR.

Joseph Hi kin BY ATTORNEY July 17, 1956 J. HIGHKIN METHOD OF ANDAPPARATUS FOR MAKING DENTURES Filed Aug. 20, 1954 3 Sheets-Sheet 2INVENTOR. Joseph Highkin ATTORNEY July 17, 1956 J. HIGHKIN METHOD OF ANDAPPARATUS FOR MAKING DENTURES 3 Sheets-Sheet 3 Filed Aug. 20, 1954 M aTn o :l T w 1 h A M H United States Patent METHOD OF AND APPARATUS FORMAKING DENTURES Joseph Highkin, New York, N. Y.

Application August 20, 1954, Serial No. 451,138

9 Claims. (Cl. 3232) This invention relates to dentistry, andparticularly to full dentures or dental plates, and to an apparatus anda process for making such dentures or plates.

One object of this invention is to provide an apparatus, and a methodutilizing the apparatus, for making dentures or complete sets ofdentures or plates so they can have freedom of relative transverse orlateral movement in response to mastication motion of the mandible orlowerjaw.

In forming dental plates, mainly as full plates to replace the entirearch of a set of teeth, it is naturally desirable to form the plates insuch a manner that the two sets of plates of artificial teeth will fittogether to provide the natural bite and follow the relative motionestablished by masticating motion of the jaw structure of the wearer.

The natural bite and motion of a natural set of teeth normally includesa vertical motion, or relative up-anddown movement of the sets of teeth,a relative front and back movement between the two sets of teeth, and arelative lateral or transverse oval movement of the two sets of teeth.Such relative movement between the upper and lower jaws of the mouth ispossible because of the nature of the pivotal support of the lower jawon the two rear hinge points where the lower jaw is supported on themaxillary or upper jaw.

One of the problems in shaping engaging tooth surfaces of artificialtooth plates 'has been due to the lack of an articulator or mechanicaldevice that could reproduce all of the movements of the human jaw, whichwould then permit the dental operator to correspondingly shape the platethat was to be fitted to that jaw, so the plate could respond to all ofthe movements of that jaw.

One of the primary objects of this invention is therefore to provide anarticulator which can reproduce the entire range and degree and type ofmovement of each jaw of an individual for whom the dental plates are tobe made.

Another object of this invention is to provide dentures so properlymated as to enable the wearer to substantially reproduce the relativemovements originally enjoyed with his natural teeth.

The general method of operation involved herein, contemplates severalsteps, to obtain a record or diagram of the patients jaw-settingposition, and of the relative movements of the two jaws in the variousbiting and grinding or chewing operations.

Those records are used to form control surface elements or cams for anarticulator, on which certain movable elements serve as mechanicalfollowers to control the shaping and inclination of the surfaces of theengaging artificial teeth in the two engaging dentures or plates to beprepared to be worn by the patient.

The steps of the dental procedure for forming the dental plates by meansof the articulator, and the detailed construction of the articulator,may be more readily comprehended upon reference to the drawings, inwhich:

Figure 1 is a schematic open view of auxiliary denture Patented July 17,1956 "ice models for application to two arches of a human mouth that areto be equipped with artificial plates;

Figure 2 is a front schematic view showing the auxiliary models of Fig.1 in closed position with scribing pins applied;

Figure 3 is schematic front view, in perspective, of the two denturemodels of Fig. 2 in open position to expose the scribing pins and recordplate supported on the two models;-

Figure 4 is a schematic front view, in perspective, of the two auxiliarydenture models of Fig. 3, in open position, with the markingsrepresentative of the range of relative movement of the patients jawsduring mastication;

Figure 5 is a schematic front perspective view of the auxiliary denturemodels of Fig. 4 in operating position on the articulator, andillustrates the bottom jaw model as being movable with respect to theother elements that are indicated to be held in stationary positionduring such movement, in order to reproduce by pantographic operation, amastifi-cation range outline of the bottom denture model in five waxmolds to provide a record for preparation of control discs for thearticulator;

Figure 6 is a schematic view, in perspective, of five conjugate molds,of plaster-of-Par-is, for making final metal control molds for thearticulator;

Figure 7 is similar to Fig. 5, except that soft wax buttons have beenreplaced by hard metallic button molds to serve as the actual camcontrols for the articulator;

Figure 8 is a front elevational view of a final set of artificial teethin the two denture plates to be worn by the patient;

Figure 9 is a perspective exploded View of the articulator of thisinvention;

Figure 10 is a perspective view of the articulator of Fig. 9 in closedposition; and

Figure 11 is similar to Fig. 10 with the finished denture plates inposition on the articulator for final processing.

The first preparatory steps are as follows:

1. An impression is taken by the dentist in suitable impression materialthat will harden in the mouth, to give impression of the full upper andthe full lower gum arches; these impressions are essentially negatives;

2. The negative gum impressions are then used in the laboratory toreceive poured stone or equivalent selfhardening material to form themodels or true reproductions of the patients upper and lower gun archesto be used in later operations;

3. The next operating step is to obtain a measure of proper verticalspacing of the patients jaws, as a guide to proper positioning of theteeth on the dentures; for that operation, an arch-shaped channel,internally filled with impression bite material, is provided for eachgum and is equipped with an outer layer of wax (so the two opposedchannels can be compressed by a direct bite, and the outer layers of waxwill be in direct contact and in compression;

4. The dentist places these two channel arches in the patients mouth forthe direct vertical bite, and the wax layers are then graduallyrespectively shaved horizontally, as may be necessary, until theirrelative size and shape hold the jaws in proper position correspondingto normal closure position of the original teeth of the patient. T hescspacing plates may then be fitted on the models of the gums to provide atrue measure of proper spacing for the patients jaws and thus guide theproper size and spacing of the dentures with the artificial teeth to bedisposed therein;

5. The two channel arches are then placed on an articulator to get theproper vertical measure, as by a vertical front pin of adjustable lengthon the articulator; the articulator is then opened and the channelsremoved,

leaving the front pin to record the proper spacing of the articulatorjaws;

6. The next step then becomes the initial procedural step of theprocedure or method of this invention, and will now be explained withreference to the drawings.

As shown in Fig. 1, two auxiliary denture models, as upper and lowe 27and 28, are formed with internal impressions formed to fit the top andbottom dental arches of the patient to be fitted, as taken from the archmodels previously made. These auxiliary denture models will be shapedfirst to have external fiat seating surfaces 24 and 25, and be properlyaligned relative to a center line 23.

These auxiliary denture models will then be equipped, as shown in Figs.2 and 3, with scribing or recording plates 31 and 32, to obtain a recordof the various possible movements of the patients jaws.

For this purpose the two metallic recording plates 31 and 32, arecemented to the auxiliary denture models 27 an 28.

The material of recording plate 31 is relatively soft so that it mayaccept a recording or scribing mark, from three marking or scribing pins33 secured to and integral with the plate 32 on the bottom auxiliarydenture 23. The auxiliary denture models and the three scribing pins areformed so the three pins engage the top plate at the same time, ininitial still position.

These two marking plates 31 and 32 are similar in purpose and functionto corresponding plates shown in Patent Number 1,669,335, issued May 8,1928, to David Highkin. These marking plates may be variously moditiedin form and construction, and are illustrated here in the simplestmanner, merely to indicate the purpose and function of the plates, whichis to obtain a record of the nature and extent of movement possible bythe jaws relative to each other in the patients mouth, as duringmastication.

The individual auxiliary denture models 27 and 28, as now equipped withthe recording plates 31 and 32, are then placed in the patients mouth inorder to obtain such record of his jaw movements. Such a record ofmarkings resulting in a groove or concavity is indicated the upper platein Fig. 4. Each of the three marking pins 33 will have formed a grooveor cavity 35 in the upper plate 31. The two auxiliary denture models 27and 21%, with the record grooves 35 in the plate 31, are now ready foruse on the articulator, to serve as guide controls in the designconstruction of the final dental plates with the artificial teeth. Atthis stage of the procedure, the scribe or bottom plate 32 with thesharp pins 33 of Fig. 4 is removed, and a plate of similar size anddimensions, shown as plate 37 in Fig. 5, is substituted for plate 32 onthe bottom auxiliary denture 28.

A functional disposition of the control plates 31 and 3'? and thesupporting auxiliary denture models 27 and 23 on the articulator isrepresented schematically in Fig. 5. The substituted plate 37 isprovided, however, with pins of equal length to the pins 33 but withrounded heads 39, which may be merely blunt points, but are shown asenlarged rounded heads solely for illustrative emphasis. The upper plate31 is retained, however, with its record grooves 35 which now serve ascam surfaces to guide and control the nature and extent of movement ofthe blunt points 39 of the pins on the substituted lower plate 37. Interms of cam theory, the lower plate 37 may be considered a cam followerplate.

The lower plate 37 is indicated as being relatively movable in bothdirections laterally by the double headed arrow 41, to indicate that theentire lower denture 28 with the follower plate 37 is thus movable.

The upper plate 31 with the record grooves 35 is indicated as being heldstationary on the articulator, by the symbolic indication of thestructural backing.

Similarly, five other elements are shown as being held in stationarypositions on the stationary supporting structure of the articulator.These five elements are shown as wax disc elements, two of which marked44 and 45 are supported above the transversely movable bottom model 28and plate 37, and three other similar disc elements 46, 47 and 43 aredisposed below that transversely movable model 28 and follower plate 37.Each of the five wax discs 44 to 48, inclusive, is indicated to be heldin anchored position by the articulator structure, indicated in eachcase by a structural symbol 49.

The lower jaw auxiliary plate model 28 is mounted, as previously stated,for lateral or transverse movement in both directions horizontally, asindicated by the arrow 41. For this purpose, the auxiliary plate model28 is supported on a movable frame of the articulator, as indicatedgenerally by the broken dash line 51, so that the lateral or transversemovement, of the lower jaw auxiliary plate model 28, is imparted to fivescribing elements supported on the frame 51 of the articulator.

Those five scribing elements, marked 52 to 56, inclusive, engage the waxdiscs 44 to 48, inclusive, and form grooves or markings in those waxdiscs, corresponding to the cam groove markings 35 in the stationaryupper auxiliary plate model 31, as the follower pins 39 are moved inthose cam grooves 35 in said upper plate model 31.

The grooves 57 that are thus now formed in the wax discs 44 to 48,inclusive, are similar to the original records or grooves 35 that wereformed directly by the patient with plates 31 and 32 in his mouth, theonly difference being due to the difference, if any, in the dimensionsof the grooves or records 57 made on the articulator because of therelative dimensions of the pantographic action of the articulator.

The function of the wax discs on the articulator is to serve as easilydeformable models from which hard metallic discs may be formed, havingthe same contour grooves or cavities, which will then provide rigidcontrol surfaces in the nature of cam surfaces in material that isrelatively Wear-resisting. Then the articulator may be operated againstthose wear-resisting surfaces as cam surfaces without any loss ofaccuracy in reproducing the functional movements of the patients jaw, asa guide toward forming proper inclined surfaces on the ultimateartificial teeth.

In order to form such wear-resisting cam buttons or discs, the wax discs44 to 48, with the grooves formed therein, are removed from thearticulator, suitable conjugate molds 59-12 to 59-2 are formed ofplaster-of-Paris, using conventional dental techniques, and then theultimate metallic buttons 61 are formed from the plaster-of Parisconjugate molds 59, to provide final cam discs 61-a to 61-e as in Fig.7, which have the same shaped cavities and recesses that were originallyformed in the wax buttons 44 to 48, inclusive.

The metallic cam buttons 61a to 6le, of Fig. 7, are now placed incorresponding positions in the articulator, as substitutes for theoriginal respective wax buttons 44 to 48. This articulator is now readyfor any of the mechanical or grinding operations that may be necessaryfor properly locating and shaping the artificial denture teethultimately on their supporting plates, to enable those teeth to havefree movement in response to masticating operations of the patientsjaws. Such proper shaping of the artificial teeth prevents any traumaticstresses that would tend to displace the plates of the patient fromtheir proper positions during such masticating operations. The finalappearance of the dentures is generally indicated in Fig. 8.

In a variant procedure, the plaster-of-Paris conjugate molds may beformed in the articulator itself, directly on top of the several scribedwax discs. When such plasterof-Paris molds are hardened, the wax may bemelted out through suitable passages, and replaced by molten metal,using standard dental techniques. Upon solidification of the metal toform duplicates of the scribed wax discs, the plaster-of-Paris molds maybe removed to expose the metallic cam buttons thus formed.

Referring now to Fig. 9, the elements of the articulator 70 of thisinvention are shown with the several parts separated for simpleillustration.

The articulator 70 comprises a base or platform 71 extending backwardlyinto two vertical standards 72 and 73 that serve as supports for apivoted shaft 74. That shaft 74 carries an arm 75 to support andposition various elements representative of the upper jaw of thepatient. Shaft 74 also carries a pivoted locking and spacing post 77 forcontrolling the proper elevation or vertical disposition of the upperjaw support element 76 on the articulator. The articulator 70 furthercomprises a bracket 80 to support the denture elements 81 associatedwith the lower jaw of the patient. This articulator, as illustrated inFig. 9, is intended toreproduce all of the mandibular gyrations ofmastication, which have been generally referred to above as the possiblerelative movements of the two jaws of the patient.

Returning now to the platform or base 74, for a more detaileddescription of its construction, it will be observed, in Fig. 9, thatthe base is provided with three bosses 82 suitably recessed from the topsurface of the base 71 to receive and accommodate first the wax buttons46, 47 and 48 indicated in Fig. 5, and then, later, the metallic buttons61-0, 61-a', and 61-e shown in Fig. 7. In accordance with the variantprocedure previously referred to, the wax buttons 46, 47 and 48, afterbeing scribed may be covered, in place, in the bosses 82, withplaster-of-Paris, to form hardened inverted molds in the bosses. The waxmay then be melted out through suitable openings in the side or bottomof each boss, and molten dental metal substituted to form hard metalliccam button discs, shaped by the plaster-of-Paris molds to correspond tothe removed scribed wax discs.

The front edge of the base 71 is provided with a slot 85 to receive aportion of the shank at the front or lower end of the positioning rod77, as, for example, between two positioning stop nuts 86 and 87 on thatrod. A coiled helical spring 88 serves to provide an additional holdingforce to press the positioning nuts 86 and 87 together, to prevent anycasual displacement of the rod during work on the articulator.

The two vertical standards 72 and 73 that rise upward from the base orplatform 71 support two similar bosses 89 and 90 that serve as retainingcups, first for the wax buttons 44 and 45 of Fig. 5, and later for themetallic buttons 61-a and 61b of Fig. 7.

The mandible or lower jaw element 80 of the articulator may now beconsidered in its detailed construction and functional operation. Thatelement corresponds, in operation, on the articulator, to the mandibleor lower jaw of the patient. The mandible consists, as indicated in Fig.9, of a base or platform portion 91 with two backwardly extending sidearms 92 and 93 suitably braced and connected by a cross-bar. The topends of the two side arms 92 and 93 respectively support two pivot pins95 and 96, whose lower bluntly rounded ends function respectively as camfollowers, or guide pins, when seated in the cam discs61-a and 61-1: inthe two retaining seats 89 and 90 on the side arms of the main base 71.The base 91 of the mandible 80 is similarly provided with three guidepins 97, 98 and a third pin that is not visible in Fig. 9. These bottomguide pins 97, 98 and the unseen third pin, fit into the cam discs 61-0,til-d and 61-e in the base 71.

The action of the articulator 70 may now be better appreciated uponreferring to Fig. 10. It will be observed that the mandible frame 80resembles the mandible or lower jaw of the patient. The two upper pivotpins 95 and 96 at the top of the mandible frame 80, of which only thepivot pin 95 is visible in the showing in Fig. 10, are relatively freeto move within the limits of the concave markings 100 and 101 reproducedin the cam discs 61-11 and 61b.

In similar manner, the three pins 97, 98 and the third pin on the underside of platform 91, are seated in the 6 cam discs 61-c, 61-d and 61e,that are anchored in the respective pockets of the bosses 82 on the baseof the bottom base plate 71.

The mandible is thus free to move at its upper end, where it issupported by the pivot pins and 96, and is similarly free to move at itslower end, where it is supported by the pivot pins 97, 98 and the unseenthird pin.

Since the cavities in the metallic cam discs 61a to 61e correspondessentially to those formed and established in the initial test platesby the actual jaw movements of the patient, these cavities in thecontrol discs of the articulator will, in turn, cause a type of movementbetween two artificial plates that are supported on the articulator,that will correspond to'the movements which the test plates experiencedwhile being moved in the mouth of the patient in response to his generalmasticating jaw movements.

In order to hold the two movable plate elements of the articulatorwithin a predetermined limited range of relative movement, the mandibleelement 80 is pivotally floated on the base plate 71 by means of tworesilient pivots formed by two individual helical springs 104 and 105 ateach side edge of the mandible 80, at a region directly behind the base91 of the mandible 80.

These two pivotal springs 104 and 105 are mounted on supporting pins 106and 107 which extend through appropriately positioned holes 108 and 109in the mandible frame 80. When the two pins 106 and 107 are pressed downthrough similarly positioned holes 111 and 112 in the base 71, the pinsare then suitably anchored against casual displacement by the insertionof a pin or thin rod through the eyes 114 at the lower ends of the rods106 and 107.

The mandible frame 80 is thus pivotally supported on the base 71 so thesame full degree of relative movement between the two frames of thearticulator may be established, that corresponds to the same relativemovements in the jaw of the patient, from whose movements the severalcontrol discs have been shaped.

The final operation of shaping or grinding the teeth surfaces after theteeth have been assembled on the plates that are to be fitted to thepatient, may be readily realized upon reference to Fig. 11. As thereshown, the two final dental plates or dentures are assembled on thearticulator where they may then be subjected to the same relativemasticating movements that will occur in the mouth of the very patientto whom they are to be fitted.

Under the conditions which dictated the forming and shaping of thecontrol disc buttons, the cam control action of those buttons, in turn,assures that the tooth surfaces of the two dental plates will be shapedto have the exact inclinations that will be necessary to enable thoseteeth to move relatively to each other without introducing traumaticshocks or stresses that would cause discomfort to the patient or woulddislodge the dentures from their proper normal positions.

Appropriate relief or relative separating movement between the twodental plates during such grinding-in operation is permitted by thecompressible spring 88 at the bottom of the front spacing pin 77, and bythe pivoting compressible helical springs 104 and 105 between themandible bracket 80 and the base.

By means of the articulator herein disclosed, it is now possible toduplicate the full and exact movements of 'a patients jaws, so as to beable to make a set of dentures whose tooth surfaces have proper relativeinclinations to enable the teeth to move properly without interference;

The invention is not limited, of course, to the specific details ofconstruction of the articulator itself. In the general form thearticulator does resemble the conventional articulator, but it has beenmodified to embody various features of construction that enable theparts to move and operate in accordance with the movements of the humanjaw.

What is claimed is:

1. An articulator comprising a main base plate for supporting an upperdenture; a mandibular frame structure for supporting a lower denture inengagement with the upper denture; means for supporting the mandibularframe for relative movements on the main base plate to reproduce theuniversal gyratory movements of a human mandible during mastication;means constituting scribed cam disc records representative of suchgyratory movements in the mouth of the patient; means holding said camdisc records in pro-determined fixed positions on the main base plate;and means fixed on the mandibular frame and constituting cam followerpins to ride in the cam disc records and guide the movements of themandibular frame.

2. An articulator for reproducing the mandibular gyrations ofmastication, comprising a main base plate having a platform at the frontof the base plate and two vertical posts at the rear of the base plate;a socket element supported on each vertical post; a mandibular elementhaving a front platform and two side rearwardly extending arms, with adownwardly depending pivot pin on the back end of each arm, the pivotpins being adapted to be seated in the socket elements and to havefreedom of movement therein; three socket elements supported on andwithin the platform of said main base plate; three pivot pins dependingfrom the front platform of the mandibular element and fitting into saidthree sockets respectively, and being adapted to have freedom ofmovement therein; means pivotally supported from the two vertical postsof the main base plate and serving to hold an upper denture inpredetermined fixed position above the platform of the main base plate;and means on the mandibular element for holding a lower denture inoperative position relative to the upper denture to enable the twodentures to be mated.

3. An articulator comprising a base having two spaced posts; an armpivotally supported for angular movement about a horizontal axis acrosssaid posts from a non-operating position to an operating position abovethe base; a pole of adjustable length for supporting the free end of thepivoted arm at a selected height above the base; means for supporting anupper denture plate on the under side of the pivoted arm; a frame havingthe general form of a human mandible or lower jaw for supporting a lowerdenture in a position under an upper denture on said pivoted arm; springmeans pivotally supporting said frame and biassing the frame upwardlytoward said arm to cause the two dentures to engage when the arm and theframe are in place; means supported from the under side of the lower jawframe to serve as follower elements to guide and limit the relativepivotal movement of the frame on its pivotal supports; and guide meanssupported on the base and adapted to be engaged by the guide followerelements, said guide means having pre-shaped cavities whose surfacesserve as cam surfaces to control the movement of the guide follower elements during manual manipulation of the jaw frame to establish propercorrelation between the two dentures for mastication movements.

4. The method of making an artificial denture and shaping the denture onan articulator, which consists in generating a record of the universalrelative movement of a patients lower jaw relative to the upper jaw;preparing models of the gum arches; preparing and fitting dentures tosaid models of th gum arches; subjecting the two dentures of a matchedpair to gyratory movements corresponding to mastication; and utilizingthe record of the patients jaw movements as a control guide in shapingthe inclination of the engaging surfaces of the denture teeth as thedentures are correlated on the articulator.

5. A method as in claim 4, in which the record of relative jaw movementof a patient is formed as a cavity in a soft wax material; and then thecavity is reproduced exactly in a wear-resisting material to serve as aguide cam surface for controlling the relative movements of the finaldentures to establish the required correlation between them.

6. An articulator for reproducing the mandibular gyrations ofmastication, comprising a main base member, cam disc records on saidbase member representing gyratory movement of a human mandible duringmastication, a mandibular element, means fixed on the mandibular elementand constituting cam followers engaging the cam disc records for guidingthe movement of the mandibular element, means on the mandibular elementfor holding a lower denture, a member movably attached to the base andoverlying said mandibular element, and means on said last member servingto hold an upper denture in operative position relative to said lowerdenture.

7. The combination of claim 6, in combination with resilient means topress said overlying member toward said base whereby to resilientlypress said dentures toward each other.

8. The combination of claim 6, said overlying member being pivoted tosaid base member, a rod pivoted to said overlying member, and springmeans on said rod engaging said base.

9. The method of making an artificial denture which comprises takingnegative impressions of upper and lower jaws in an edentureless mouth,then making upper and lower positive models from said negativeimpressions, then making base plates complementary to said upper andlower models, then applying a bite rim of relatively soft material tothe upper of said base plates and fastening hard pins to the lower ofsaid base plates, then placing the base plates in a patients mouth andhaving the patient perform the mandibular gyratory movement whereby saidpins form grooved cam records in said bite rim representing the gyratorymandibular movement in the mouth of the patient, then placing the modelswith the base plates into an articulator in which the upper model baseplate and bite rim is stationary and in which the lower model base platewith its pins can move following the movement of the pins within saidcam records, then making permanent record discs from the movement of thelower model and base plate, and forming upper and lower dentures toreplace the upper and lower base plates and placing them on the upperand lower models in the articulator, and causing the lower model andlower denture to move, following the record disc whereby the teeth ofthe lower denture will have movement corresponding to the mandibularmovement relative to the upper jaw, and putting grinding materialbetween the teeth during such movement whereby the teeth may be ground.

References Cited in the file of this patent UNITED STATES PATENTS2,608,761 Scott Sept. 2, 1952 FOREIGN PATENTS 364,815 Germany Dec. 2,1922

